1. Technical Field
The present invention relates to a digital modulator, a digital modulation method, a digital transceiver system, and a test apparatus. In particular, the present invention relates to a digital modulator, a digital modulation method, a digital transceiver system, and a test apparatus suitable for integration and restricting power consumption.
2. Related Art
An IQ modulator is often used for digital modulation, as shown in Japanese Patent Application Publication No. 2004-274243. The IQ modulator includes an oscillator and two multipliers that output a carrier wave, a phase shifter that shifts the phase of the input signal by 90 degrees and outputs the thus shifted signal, and an adder.    Patent Documents cited: Japanese Patent Application Publication No. 2004-274243.
However, since the digital modulator is realized through an analog circuit, the implementation area and the power consumption become undesirably large.